22 THE SPIRIT OF THE SOIL 



the wonder of them far transcends all that the 

 imagination of the poet has conceived. In setting 

 aside the romance of the past the laboratory is 

 guiding us to an astonishingly greater romance of the 

 present. The child's " Let us pretend," a pitiful 

 attempt to furnish the food that its imagination 

 demands, gives place to the cry of " Let us know,' 1 

 and in imaginative splendour the knowledge of 

 to-day presses out beyond all that was previously 

 conceived. 



Who in the past could have imagined the mys- 

 terious happenings that take place in a small plot of 

 garden soil ? It was a revelation to the world when 

 Darwin, lifting a corner of the veil, told of the stu- 

 pendously great part played by the earthworm that 

 had been " carrying on " unheeded or resented for 

 countless ages of time. But to-day we are beginning 

 to know that the soil which the gardener turns with 

 the spade is the site of countless vast empires of 

 bacteria. They are empires that rise and fall in the 

 short space of weeks, that have great tasks to per- 

 form, and devote themselves wholeheartedly to 

 carrying them out, empires liable to countless vicissi- 

 tudes. Now they are overwhelmed by the vast 

 immigrations that come to them suddenly as gar- 

 dener or husbandman pours into their borders 

 countless myriads of individuals with each spadeful 

 of his manure. Periods of drought wreak havoc on 

 their colonies, the lives of whole empires being 

 dependent on the chances of the climate. They are 

 preyed on by monstrous protozoa that may exact 

 a greater toll than even they with their astounding 



